RT Journal Article
SR Electronic
T1 Age and Sex Variability and Normal Reference Values for the VMCA/VICA Index
JF American Journal of Neuroradiology
JO Am. J. Neuroradiol.
FD American Society of Neuroradiology
SP 730
OP 735
VO 26
IS 4
A1 Krejza, Jaroslaw
A1 Szydlik, Piotr
A1 Liebeskind, David S.
A1 Kochanowicz, Jan
A1 Bronov, Oleg
A1 Mariak, Zenon
A1 Melhem, Elias R.
YR 2005
UL http://www.ajnr.org/content/26/4/730.abstract
AB BACKGROUND AND PURPOSE: The index of mean blood flow velocity (V) in the middle cerebral artery (MCA) divided by respective velocity in the ipsilateral internal carotid artery (ICA), or VMCA/VICA index, is commonly used as a marker of vasospasm, although reference values are not established. We sought to provide reference data for these velocities and index.METHODS: Transcranial color-coded duplex and carotid duplex sonography was performed in 335 healthy volunteers (211 women, 124 men; mean age ± SD, 42 ± 18 years; range, 18–86 years). Age analyses were based on three groups: I, <40; II, 40–60; and III, >60 years. The VMCA/VICA index was calculated based on angle-corrected blood flow velocities determined in the MCA and extracranial ICA.RESULTS: Mean flow velocities in the MCA and ICA diminished with increasing age, most pronounced in those subjects >40 years. The VMCA/VICA index increased significantly (1.67 + 0.005 [age]; P < .05) with age in women, but not in men. In women, reference values and ranges for the VMCA/VICA index were as follows, by group: I, 1.82 (range, 0.88–2.68); II, 1.91 (range, 0.94–2.88); and III, 2.06 (range, 0.59–3.53). Respective values for men were as follows, by group: I, 2.10 (range, 0.96–3.24); II, 2.04 (range, 0.71–3.37); and III, 1.78 (range, 0.81–2.75). In subjects <40 years, the VMCA/VICA index was significantly higher in men than in women.CONCLUSION: The VMCA/VICA index significantly varies with age and sex. Sonographic diagnosis of cerebral vasospasm should be based on age- and sex-adjusted reference values of the VMCA/VICA index.